Trynin A. Yu.
Estimates for the Lebesgue functions and the Nevai formula for the sinc-approximations of continuous functions on an interval
We obtain some upper and lower estimates for the sequences of the Lebesgue functions and constants of the Whittaker operators
for continuous functions. We give an analog of Nevai’s formula for the Lagrange-Chebyshev and Lagrange-Laguerre interpolation polynomials for the operators under consideration. Its “local” version is established.